Features/Opensharedroot

Feature Name

Open Sharedroot

Summary

The open sharedroot project provides abilities to boot multiple linux systems with the same root filesystem providing a single system filesystem based cluster.

Owner

• Name: Marc Grimme

• email: grimme@atix.de

Current status

• Targeted release: 12
• Last updated: 2009-07-02
• Percentage of completion: 85%

Detailed Description

The purpose of this feature is to provide an open and flexible filesystem based single system image (SSI) linux cluster.

Currently the following filesystems can be used with fedora 11:

• NFSv3, NFSv4

• GFS2

• Ocfs2

• Ext3 as local filesystem

Basically it consists of three different software components and some small changes to the initprocess.

1. The initrd (comoonics-bootimage) to boot such a system. As it is more complex to boot from a cluster filesystem or nfs in order to use in a sharedroot configuration we need a new concept of the initrd.

2. The clustertools provide access to clusterfunctionality like querying the cluster for amount of nodes and configuration. This is organized under the software component comoonics-clustersuite.

3. The management tools for building a cdsl structure (context dependent symbolic links) and managing cdsl files. This is organized under the software component comoonics-cdsls. The cdsl concept is based on bindmounts.

The changes to the initprocess are already filed in bugzillas:

• https://bugzilla.redhat.com/show_bug.cgi?id=496843

• https://bugzilla.redhat.com/show_bug.cgi?id=496854

• https://bugzilla.redhat.com/show_bug.cgi?id=496857

• https://bugzilla.redhat.com/show_bug.cgi?id=496859

• https://bugzilla.redhat.com/show_bug.cgi?id=496861

Benefit to Fedora

Being able to boot multiple nodes from the same root filesystem. Enabling fedora to be a filesystem based single system image cluster.

Scope

Except from the small changes that have to be accepted for the initprocess. Everything else is already working for FC11, RHEL5 and RHEL4. So only the migration to FC12 has to be made.

How To Test

Follow the guidlines on the project page for installing and testing.

User Experience

This project has been devolped since 8 years. We know of some hundreds of RHEL4/5, FC11 clusters that are running productivly for years. This concept is also supported by Red Hat on RHEL.

Dependencies

See bugzillas above. Basically changes are needed in initscripts and SysVinit (some are already integrated in this pakage).

Contingency Plan

None necessary.

Documentation

• Project http://www.open-sharedroot.org/
• Buzilla Instance: https://bugzilla.open-sharedroot.org/
• Mailing List: open-sharedroot-users@lists.sourceforge.net, open-sharedroot-devel@lists.sourceforge.net

Red Hat Magazine: http://www.redhat.com/magazine/021jul06/features/gfs_update/ Red Hat/ATIX/SAP Whitepaper: http://www.redhat.com/f/pdf/ha-sap-v1-6-4.pdf

Release Notes

• Filesystem based Single System Image Clusters can now be created with Fedora.

Comments and Discussion

• See Talk:Features/Opensharedroot